'Scary' science finds Earth heating up twice as fast as thought
Leigh Dayton, Science writer
27jan05
THE largest ever climate-change experiment reveals that scientists may have dramatically underestimated the threat of global warming.
The study by British scientists, which is published today, found the planet's global temperature could climb by between 2C and 11C because of skyrocketing levels of greenhouse gases such as carbon dioxide.
That more than doubles the current prediction of a 1.4C to 4.5C rise this century.
"When we started out we didn't expect anything like this," said Oxford University's David Stainforth, chief scientist for climateprediction.net.
The project is a collaboration of experts at Oxford and Reading universities, The Open University, London School of Economics, Hadley Centre for Climate Prediction and Research, and Rutherford Appleton Laboratory.
The findings are published in the journal Nature.
"If this is the case, it's very dramatic and very scary," Mr Stainforth said.
Even rises that are more modest are expected to trigger disastrous changes, including melting glaciers, sea-level rises, shut-down of the Gulf Stream, and increases in droughts, cyclones and other extreme weather events. The new results follow two reports in last week's edition of Science, showing that global warming probably caused the "Great Dying".
Although that was the worst extinction in Earth's history – wiping out more than 90 per cent of all life – it involved gradual extinctions over about 10 million years, culminating in a sharp extinction pulse 250 million years ago. Further concern comes from an international report released in London last Monday. It warned that climate change could kick in within 10 years, unless greenhouse gas emissions are cut.
The initial goal of climateprediction.net was to evaluate the sensitivity and variables of the Hadley computer model of climate change.
In order to obtain their findings, Mr Stainforth and his colleagues ran 50,000 climate simulations.
Because so much computing power was needed, they relied on help from 90,000 people from 150 countries to run the programs on their personal computers.
More than 1200 Australians, such as Melbourne academic Nick Hoffman, participated. "I'm interested in the dynamics of planetary atmospheres, so it was well worth supporting (the project)," Dr Hoffman said.
According to Neville Nicholls, head of climate forecasting at the Bureau of Meterology in Melbourne, climateprediction.net is a "terrific project" that tackles the uncertainty of climate predictions. He agreed with CSIRO climate modeller Tony Hirst that: "This may mean that the world could warm up faster than most of us are happy anticipating."
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